1. Field of the Invention
The present invention concerns a guiding, positioning and boring sensor device, adapted to be utilized for securing an intramedullary nail prior to its placing within the medullary canal or cavity of a damaged bone. It also concerns an intramedullary nail to be secured through utilizing this sensor.
The invention concerns more particularly a locking intramedullary nail, i.e. intended to be secured with respect to the bone through at least one screw crossing through two facing and aligned screw holes, previously provided in the nail and also passing through the adjacent corticals on either side of the nail, whereas the above-mentioned fixation device is intended to allow the placing in position of such a screw.
The intramedullary nail considered in the present description is of the type constituted by a quasi-tubular rigid element, especially metallic, that presents a constant non-circular cross-section on at least the major part of the length of the nail. As a general rule, nails of this type do not have a continuous peripheral wall, but define a longitudinal slot extending along the whole length of the nail.
2. Description of the Prior Art
The conventional widespread method utilized up to now for placing, or implanting, such an intramedullary nail, especially in distal position, consists essentially in boring, at one end called proximal end of the bone to be treated, an opening offering longitudinal access to the medullary canal, for introducing the nail within through this opening, by longitudinally displacing within the canal until it reaches the required depth of penetration, in marking the site and the position of the screw holes of the nail, in boring holes in the two opposite cortical zones adjacent to the said screw holes of the fixation holes aligned with precision upon the screw holes, in introducing a screw into these screw and fixation holes and in securing it through screwing in the cortical zone receiving the tip (or the fore end) of the screw, the fixation hole provided in this cortical zone presenting with this aim a diameter smaller than the diameter of the diameter of the top of the thread of the screw.
Although this is the only method that can be applied by utilizing currently available surgical equipment, it presents a serious drawback in that the marking of the sites at which the bone must be bored transversally in order to provide the above-mentioned fixation holes in exact alignment with the screw holes of the nail previously put in place, is an extremely delicate operation. In most cases, the surgeon has to use, for this purpose, the radioscopy technique, utilizing brightness amplifiers, frame finders, etc. These complicate and prolong the surgeon's labour, while extending the time period during which the patient is maintained under anaesthesia, and above all exposes the surgeon and the patient to an undue amount of X-ray radiation.